#! /usr/bin/env python
# -*- coding: utf-8 -*-
# vim:fenc=utf-8
#
# Copyright © 2018 crane <crane@crane-pc>
#
# Distributed under terms of the MIT license.

"""

"""

def comb(n, m):
    if n < m:
        return 0

    if n == m:
        return 1
    if m == 0:
        return 1

    if m == 1:
        return n
    if m == n-1:
        return n

    return comb(n-1, m-1) + comb(n-1, m)


def test():
    print(comb(5, 2))
    print(comb(5, 3))
    print(comb(5, 4))
    print(comb(10, 5))


def main():
    print("start main")
    test()


if __name__ == "__main__":
    main()
